The use of recombinantly-produced therapeutic proteins for the treatment of many diseases or conditions such as cancer and autoimmune diseases continues to increase. However, large-scale production of these protein therapeutics still remains a challenge. For example, the commercial manufacturing process must deliver a reliably high-yield with downstream processes producing an extremely pure product allowing only trace amounts, to preferably, no contaminants.
The use of animal component-free media has significantly reduced the incidence of adventitious viral contamination. Additionally, the implementation of procedures such as ultrafiltration, high temperature short time processing, and/or UVC irradiation of bulk materials has further reduced the incidence of contamination. Nevertheless, the risk of viral contamination still remains. A contamination incident would be catastrophic for the manufacturer in terms of loss of product, temporary withdrawal for the market, and extensive decontamination costs. Thus, there is a need for mammalian cell lines having increased resistance to viral infection.